Disk drive laser melt bump disk for accurate glide calibration and certification processing

Abstract

A bump disk for accurate glide calibration has a new type of glass laser melt bumps that give the same signal amplitudes as conventional AlMg laser melt bumps for the same bump height. The present invention provides a solution to switch the calibration bumps from AlMg to glass, and can be used in disk manufacturing lines to save 30% on the cost of hard disks from inaccurate glide certification processes. The solution is to trim or burnish away loose and/or high particles on production disks before the glide tests. This additional processing step causes the responses from the glass bumps to become very similar to those of the AlMg bumps, thereby enabling glass and AlMg disks to become materially compatible.

Description

[0001] 1. Technical Field[0002] The present invention relates in general to improved disk certification calibration, and in particular to an improved disk drive laser melt bump disk for accurate glide calibration.[0003] 2. Description of the Related Art[0004] Generally, a data access and storage system consists of one or more storage devices that store data on magnetic or optical storage media. For example, a magnetic storage device is known as a direct access storage device (DASD) or a hard disk drive (HDD) and includes one or more disks and a disk controller to manage local operations concerning the disks. The hard disks themselves are usually made of aluminum alloy or a mixture of glass and ceramic, and are covered with a magnetic coating. Typically, two or three disks are stacked vertically on a common spindle that is turned by a disk drive motor at several thousand revolutions per minute (rpm).[0005] The only other moving part within a typical HDD is the actuator assembly. The ...

AI Technical Summary

Benefits of technology

0015] FIG. 1 is an enlarged isometric view of a conventional AlMg disk substrate with laser melt bumps.

Problems solved by technology

The presence of asperities on the surfaces of the disks can have a deleterious effect on the performance of disk drives.

Unfortunately, there is a material incompatibility for calibration on AlMg substrates and tests performed on other materials.

Moreover, the supply of AlMg substrates used for calibration bump disks in disk manufacturing engineering is limited, such that there is an urgent need to switch all calibration devices from AlMg to another material.

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